一种有源高带外抑制导航天线设计

设计了一种有源高带外抑制导航天线,能够有效抑制弹上数据链天线的高功率干扰,适应弹上复杂电磁环境。     

中厚板的高功率激光焊接

研究和应用结果表明,采用高功率激光焊接技术可实现高速、极小焊后变形的中厚板焊接,焊接接头质量良好,某些钢种的激光焊缝和热影响区表现出远优于常规焊接的冲击韧性,为激光焊接在重大装备制造中的应用提供了有力的支撑.随着高功率激光焊接的优越性逐渐得到业内的认可,高功率激光焊接工艺必将在重大装备的中厚板焊接甚至厚板焊接中得到更为深入的应用.     

基于PXI总线弹载模块自动测试系统的设计与实现

以建立一套弹载模块自动测试系统为目标,采用了基于PXI总线结构的虚拟仪器测控技术,同时采用成熟的数据采集模块与电源模块,并配备高性能的计算机,实现了弹载模块的批产测试设备,在介绍PXI总线结构的基础上,重点介绍了该测试设备的软/硬件组成、系统结构和特点。     

嵌入式液弹阻尼器原理分析与试验研究

在过去的几十年里,直升机旋翼系统的设计都着重强调旋翼桨毂的简单化,总体趋势是减少零部件个数,减少重量,减小阻力和降低维护成本,传统的液压阻尼器和粘弹阻尼器正在被液弹阻尼器取代。随着技术和工艺上的革新,制造出带嵌入式液弹阻尼器的无轴承旋翼系统已切实可行。对嵌入式液弹阻尼器的动态力学性能进行了理论研究,介绍了其工作原理,并推导出初步构型设计计算公式,系统地对嵌入式液弹阻尼器模型试验件进行了动力学试验,研究了工作性能的各种影响因素,形成了一套完整的工程设计方法,为今后嵌入式液弹阻尼器在无轴承式直升机上的应用提供了技术支持。     

基于气动分离技术的弹丸弹托分离仿真

为了研究气动分离技术使弹丸弹托分离的情况,对其进行了模拟仿真研究。采用气动分离技术使弹丸弹托分离,基于气体动力学与摩擦力学理论,分别建立了弹托绕流模型与弹丸弹托气动分离模型。使用Fluent进行绕流仿真,得到了不同速度下弹托分离前后状态下的阻力系数,再用Simulink对54式12.7mm穿甲燃烧弹的弹丸和弹托进行分离仿真,得到了弹丸弹托分离过程的特征结果。结果表明,利用气动分离技术可以使弹托和弹丸较好地分离。上述研究为弹丸和弹托的研发、使用提供了有益的参考。     

基于动网格技术的飞机舱弹分离过程 CFD/ RBD耦合数值仿真

飞机舱弹分离瞬间特性严重影响导弹/炸弹的打击精度。采用计算流体动力学(CFD)和刚体动力学(RBD)模型耦合求解的数值仿真方法,应用网格弹性光顺和局部重构相结合的动网格技术,有效地避免了刚体运动而引起的网格畸变,仿真计算了炸弹舱弹分离后俯仰角度变化过程 .仿真结果表明,舱弹分离时向炸弹施加 1个合适的抛 射力矩,有助于炸弹在下降过程中快速地调整其打击姿态。     

鸟撞试验弹托脱壳过程模拟与试验验证

为避免在航空发动机风扇鸟撞试验中弹托在剥离时发生破损而导致其碎片飞入试验舱,开展了鸟撞试验脱弹过程的冲 击动力学研究。采用LS-DYNA动力学仿真软件对鸟撞试验中弹托与脱弹器撞击过程进行了数值仿真分析。考虑到脱弹过程中 材料高应变率的影响,应用Johnson-Cook材料模型描述了弹托和脱弹器的本构关系,采用有限元分析获取了弹托的变形、位移、应 力、动能等参数的变化过程。采用压缩空气炮进行了鸟弹发射,并将弹托变形的仿真结果与试验结果进行了对比。结果表明：弹 托变形的仿真结果与试验结果相差4.4%,证明仿真方法有效;在脱弹过程中弹托前端会张开,产生喇叭口状变形;弹托中后部的 应力水平始终保持在80 MPa以下,不会因冲击作用发生破损而导致其碎片飞入舱体。     

一代名机的诞生——记米格-21的发展过程(二)

米格-21与米格-21Φ1957年底,前线歼击机E-5已正式命名为米格-21,其主要的飞行试验业已完成,而带后掠翼的类似试验机E-2A的试验工作实际已经停止,已制成的几架E-2A型飞机主要用作飞行试验台。不过,E-5(米格-21)并未立即投入成批生产,E-5的试验机继续试验。1958年5月,E-5试验机的试验全部结束。主要试验了M<1.85、飞行高度18000米的三角翼歼击机的气动力特性。不久前,用E-4试验机试验了尾旋和M<1.45的气动力特性。E-5试验机总共试飞了98次,E-4试飞了100多次,而带后掠翼的试验机E-2和E-2A则试飞了250次。     

高功率发射机的通用组合微波功率模块

主要介绍了用于高功率发射机的通用组合单元——微波功率模块(MPM)。MPM具有高效率、高增益、重量轻、体积小等优点。MPM已经在雷达、电子对抗和通讯等领域得到应用。随着技术的日益发展,MPM将会得到越来越广泛的应用。     

地基深空网发射机现状及未来发展

我国未来深空探测工程的发展对地基深空站发射机提出了更高的要求,不仅仅需要具有更高的输出功率,同时需要解决发射机高频谱纯度、高效率以及上行功率合成等。针对这些要求,对国内外地基深空网的组成和深空站高功率发射机现状以及未来发展趋势进行了研究,分析了速调管发射机与固态发射机在高功率输出条件下的优势,在此基础上,提出了我国深空站速调管发射机需要开展高功率连续波速调管、高功率低损耗滤波器、低纹波高功率开关电源、上行功率合成等关键技术,并为相应关键技术提供了理论建议及相应的解决方法,这可以为我国未来深空探测工程高功率发射机研制提供技术支撑,为后续地基深空网建设和发展提供参考。     

Power Electronics in Space: A Review and Projection

Power electronics has emerged as a distinct field of electrical engineering in recent years. This emergence is closely linked with the development of power control and conversion equipment for space application over the last 20 years. Development of switched-mode power conversion techniques has been the dominant activity in this field, spurred by both the improvements in solid-state power devices and the needs of space systems for light weight, highly efficient techniques for dc power regulation. This history is reviewed and projections are made in the four key areas of circuit fundamentals, components, circuit practice, and applications.     

Research progress of space non-pyrotechnic low-shock connection and separation technology (SNLT): A review

Space missions have become diversified in recent years, where connection and separation devices play a crucial role as key components of various spacecraft. Traditional pyrotechnic devices have the advantages of large carrying capacity, rapid motion and functional reliability. However, their shortcomings such as great release shock, poor safety, unrepeatability and other prominent defects make them unsuitable for new generation spacecraft such as microsatellites to separate at low shock or lock repeatedly, etc. Therefore, it is necessary to develop space non-pyrotechnic low-shock connection and separation devices (SNLD) which are required for advanced aerospace missions. In this paper, the progress of the research on space non-pyrotechnic low-shock connection and separation technology (SNLT) is summarized and reviewed. Proceed from the principle of reducing shock for non-pyrotechnic devices, present studies are classified from the perspective of actuating technology and systematic designing methods. For non-pyrotechnic actuating techniques, according to different driving sources, the separation devices are classified into several main categories: electric, magnetic, gas and thermal actuating devices. The actuation principle and application prospect of separation techniques are introduced and the working process, dimension and mechanical properties of typical devices are compared and evaluated. For the systematic designing method, the common mechanism types of SNLDs are summarized according to the designing concept of reducing shock. Then connection configurations are classified according to the structural forms of connection devices, of which the principles, bearing capacities and general applications are discussed. This paper systematically summarizes the key problems, puts forward the future development trend of SNLT, and points out the breakthrough direction for related scholars.     

Design Considerations for Differential Low-Level Junction FET Commutators

The many advantages of junction field-effect transistors (FET) in commutation applications have prompted a serious effort to extend the technology without sacrificing performance and, in many areas, to realize an improvement over low-level commutator performance attainable by more conventional electronic means (especially Bright switches), so that these devices may be employed in general application, high-accuracy, low-level commutation. This paper is devoted to a generalization of knowledge recently gained during the development of such equipment, which will aid potential designers and users in their understanding and application of low-level FET commutators. A discussion of device characteristics is offered as the starting point of design. A number of topics are then discussed, including offset drift and scatter, gain drift and scatter, source and amplifier loading, crosstalk, and common-mode rejection. Also, several useful design guidelines, in the form of generalized expressions, are derived or furnished for the reader's use. Finally, in order to lend veracity to the design techniques suggested, the performance data of a low-level FET commutator developed following these techniques are offered for consideration.     

汽车车速传感器的电磁兼容设计

电磁兼容性作为汽车电器可靠性参数日益受到重视。针对汽车车速传感器所面临的电磁兼容问题提出了一种设计方案,应用该方案的车速传感器电磁兼容性测试结果符合速度传感器通用技术条件的整体误差标准,并在实际应用中获得了预期的效果。该电磁兼容设计方案对汽车中其他电子设备的电磁兼容性设计同样具有参考意义。     

碱金属原子气室研究进展

碱金属原子气室是原子陀螺、原子磁力仪和原子钟等量子仪表的核心部件,高性能微小型原子气室是制约上述量子仪表性能的重要因素之一。从理论基础、制造工艺和材料等方面回顾了原子气室的研究进展,对微型气室玻壳精密加工技术、原子气室精确充制技术、耐高温抗弛豫镀膜技术、原子气室后烘处理工艺等相应关键技术进行了分析和讨论,并针对量子仪表微小型、高精度、集成化的发展需求,分析了碱金属原子气室的发展趋势。     

Fault self-repair strategy based on evolvable hardware and reparation balance technology

In the face of harsh natural environment applications such as earth-orbiting and deep space satellites, underwater sea vehicles, strong electromagnetic interference and temperature stress,the circuits faults appear easily. Circuit faults will inevitably lead to serious losses of availability or impeded mission success without self-repair over the mission duration. Traditional fault-repair methods based on redundant fault-tolerant technique are straightforward to implement, yet their area, power and weight cost can be excessive. Moreover they utilize all plug-in or component level circuits to realize redundant backup, such that their applicability is limited. Hence, a novel selfrepair technology based on evolvable hardware（EHW） and reparation balance technology（RBT） is proposed. Its cost is low, and fault self-repair of various circuits and devices can be realized through dynamic configuration. Making full use of the fault signals, correcting circuit can be found through EHW technique to realize the balance and compensation of the fault output-signals. In this paper, the self-repair model was analyzed which based on EHW and RBT technique, the specific self-repair strategy was studied, the corresponding self-repair circuit fault system was designed, and the typical faults were simulated and analyzed which combined with the actual electronic devices. Simulation results demonstrated that the proposed fault self-repair strategy was feasible. Compared to traditional techniques, fault self-repair based on EHW consumes fewer hardware resources, and the scope of fault self-repair was expanded significantly.     

基于混合 MOM-PO的复合电磁散射问题分析

海面(或地面)环境中目标电磁散射特性,对实际战场环境下军用目标的雷达探测、雷达特性形成以及雷达目标识别等技术具有基础支撑作用。因此,快速准确地分析目标和粗糙面复合电磁散射特性具有重要理论意义和应用价值。文章采用基于矩量法(MOM)和物理光学法(PO)的混合方法MOM-PO分析了目标和粗糙面复合电磁散射问题。与传统的矩量法相比,该方法在保证精确度的前提下大大加快了计算速度。     

Improved adaptive clutter cancellation through data-adaptivetraining

Adaptive array algorithms based on sample matrix inversion (SMI) require the availability of a secondary data set to “train” the adaptive filter. Numerous data-independent rules have been proposed for selecting this training data. However, such rules often perform poorly in inhomogeneous environments. We present data-adaptive methodologies for selecting the training data. The techniques, called “Power Selected Training” and “Power Selected Deemphasis”, use measurements of the interference environment to select training data. This work describes these algorithms and their performance on recorded radar data     

微动疲劳损伤试验设计研究

研制了微动桥式试验装置及试验方法。高低周复合加载由改装过的PW3-10型疲劳试验机来实现。使用应变片弓形元件测量微位移幅值。用弹性环实现微动桥和板状试件上法向接触压力的加载,利用本文中的方法及装置,已成功地完成了钛合金TC-11对高温合金GX8的微动疲劳损伤试验。     

MATLAB在电力电子和运动控制系统实验教学中的应用

根据电力电子技术和运动控制系统课程的现状，提出了一种基于Matlab的Simulink和Power System工具箱来设计电力电子电路和运动控制系统的教学实验，并给出了仿真实例。实践证明，利用电力系统工具箱作仿真，学生能较快地理解课程理论，学会仿真分析复杂电力电子电路和系统问题的技能。